I thought Star Fox looked like quite nice in motion. I do understand the dissatisfaction with its presentation, though. I think I would have felt personally very angry at Star Fox's visuals if I had not played Smash Bros. 4. With that game, I absolutely felt that it looked too plain, going in (although at face value I wouldn't disagree that it comes off very favourably against Star Fox). But I ultimately ended up finding Smash's presentation beguiling because of the game's in-motion interplay of bright colours, fluidity and speed. The seamless momentum of it all was hypnotic, and I think the gracefulness of the game-play transformed the way I looked at the game's visuals--it was as if I was looking at them through a new pair of eyes, and somehow I couldn't see them as disappointing anymore.
I think the recent memory of that above phenomenon is what makes Star Fox look nice enough to me, in that it moves with that same hypnotically fluid momentum--and thoughts of Smash give me confidence in the potential of what that momentum could do for the game's look. I could be well off the mark, but my impression is that, if it were me playing the game at E3, I might get lost in its flow in the same way that I did with Smash Bros, and start to see something new in the visuals. I just got a sense of that, watching Treehouse Live. But that's just me and I don't want to jinx anything or make a premature judgement, because I do love Star Fox and I do hope for the best for the game.
I think the concept artwork that comes with the game looks quite smart, at any rate.